1. Field of the Invention
The present invention relates to a socket for feeding electric power to electric appliances and the like, and more particularly to a socket provided with a plug locking mechanism for preventing a plug from falling off from the socket in case of electrically connecting the plug having a cord connected with an electric appliance or the like with the socket.
2. Description of the Related Art
Details of a conventional socket have been disclosed in a Japanese Kokai No. Sho 56-13678, for example.
The conventional socket has a plate member, a receptacle part, a pair of projecting parts, and a tap. The plate member has an opening at a specified position thereof. The receptacle part is embedded in and fixed to the plate member so as to expose its obverse face from the opening of the plate member. The pair of projecting parts are respectively fixed on both sides of the receptacle, namely, on both sides of the opening of the plate member. Each of the projecting .parts is made of an elastic member and has an inwardly oriented claw on its top end. The tap has a receptacle part on its upper surface as well as a pair of plug blades projecting downward on its bottom surface. This tap is provided with shoulder parts to be freely engaged with and released from the pair of projecting parts on both sides thereof.
Connecting operation of the conventional socket is described below.
First, a pair of plug blades provided on the lower surface of the tap are inserted into the receptacle part fixed on the plate member. Next, the tap is fixed on the plate member by engaging the claws of the pair of projecting parts set on the obverse face of the plate member on both sides of the receptacle part with the shoulder parts provided on both sides of the tap. Lastly, electrical connection is finished by inserting a plug having a cord of another electric appliance into the receptacle part provided on the upper surface of the tap.
However, the above-mentioned conventional socket has the following problems.
First, the conventional socket must have some special retaining mechanisms, for example, projecting parts and shoulder parts provided on both of the plate member and the tap in advance in order to prevent the tap from falling off from the plate member.
Second, since a plug with a cord of another electric appliance is simply inserted into the receptacle part provided on the upper surface of the tap, the plug with a cord easily falls off from the receptacle part provided on the upper surface of the tap when a strong pulling force is applied to the cord connected with the electric appliance,
Third, when using electric appliances whose plugs have cords with various shapes and sizes, the socket needs to be equipped with specific retaining mechanisms matching the shapes and sizes of the respective plugs with cords, and as a result it becomes poor in general usability as well as high in cost by taking much time and labor.